A conventional infrared receiver disclosed in Taiwanese Invention Patent No. I240501 includes a filter which may be utilized to block optical noise having wavelengths other than the wavelengths of infrared, so as to improve performance of the infrared receiver. However, the filter cannot block optical noise having wavelengths falling within the infrared wavelength range, so illuminance of the optical noise having wavelengths falling within the infrared wavelength range, in addition to illuminance of an infrared signal, would both be detected by the infrared receiver. If the illuminance of the optical noise is so high as to interfere with the infrared signal, the infrared signal received by the infrared receiver may be more prone to errors.
U.S. Patent Application Publication No. US 2013/0330089 A1 discloses a background noise-immune LED-based communication device, which includes at least one LED signal transmitter emitting a Manchester code signal generated by a Manchester coding technology, created in an attempt to decrease noise interference and promote signal quality. Nevertheless, if strength of background optical noise surpasses a certain extent, performance of the Manchester code signal may be adversely affected.